Reflex skill development devices for practicing skills necessary in athletic games such as baseball have been known for some time. Such devices are useful for practicing among other skills, the skills necessary for batting and catching of balls in the game of baseball. For example, a batting aid is described in U.S. Pat. No. 4,577,864 to Michael A. Aldrich comprising a molded foam rubber ball secured through a braided tubular rope and an elongated wand or a handle. U.S. Pat. No. 4,032,145 to Max M. Tami discloses a spherical baseball affixed at one end of a long nylon cord with a flexible handle fastened at the opposite end and a slide control mounted between U.S. Pat. No. 3,907,287 to Fox et al, discloses a hollow, perforated, substantially rigid ball secured to one end of a tether line, the opposite end of which is spring attached to a handle through pivoting and rotating members.
Devices for practicing the reflex skills required in catching a ball are described for example, in U.S. Pat. No. 3,843,126 to Leon D. Bandy. This patent describes a catching practice device comprising a rubber ball secured to one end of a tether line, the opposite end of which is attached to a partial glove. Another catching practice device is described in U.S. Pat. No. 3,731,927 to Thomas J. Rocco Jr. showing a ball made of knotted rubber bands tethered to a glove by a stretchable elastic rubber cord.
Additionally, erratic balls have been known for some time in the art. U.S. Pat. No. 2,362,064 to Giesinger describes a balanced ball with a highly irregular external surface which rebounds erratically upon striking a surface. U.S. Pat. No. 890,920 to Newbold teaches a ball with differing diameters and planes of section which, when thrown in such a way to hit and bounce upon the ground, will return to the person throwing it.
Balls with erratic behavior in other aspects are also known as disclosed in U.S. Pat. No. 1,629,364 to Scholly which teaches a throwing play ball with an enlarged portion on one side to cause the ball to behave erratically when thrown from one person to another. U.S. Pat. No. 1,346,991 to Tatum teaches a ball with a metallic strip on its interior and a means for holding this strip to one side of the center of the ball to provide for a ball which, when rolled, returns to the person who rolled it.